1. Field of the Invention
The present invention relates to a system for locating faults in multiplex cables which include an uncovered conductor along with strands of insulated conductors, which system includes the application of an electromagnetic or dielectric field after separation of the uncovered conductors from the insulated ones. By means of a rotating wheel or disc, at which the testing of the cable is done, the insulated, plexed cable is separated and then put back in its plexed state.
2. Prior Art
There has been a long-standing need for a satisfactory method of locating dielectric failures or insulation faults caused by holes in the insulation in a multiplex conductor.
Normally these faults in regular cables can be located by water testing, or by rewinding the cable and sending it through a spark tester.
However, in the case of a multiplex cable, there is a bare conductor present, which prevents it from being run through a spark tester. In a multiplex cable, there are typically three insulated wires and one bare wire stranded together.
The prior art "water test" way to test for faults is very time consuming. The cable is put in the water test tank, a voltage is then applied to the water, and, based on the results, the operator would know whether or not there was a fault in the conductors, but would not know the location of the fault. After discovery of a fault, the cable would have to be rewound and cut into two pieces. These two pieces would then be put back in the water tester and that portion containing the fault would be isolated. The faulty portion of the cable would then be scrapped because the length quickly got too short to test.
Another prior art way was to rewind the cable from one winder to another. Using this procedure an operator would wind off 20 to 30 feet of wire and drop it into the water tester and apply voltage to it. This method is dangerous to operating personnel near the cable.
These prior art techniques are thus "blind" tests depending substantially on trial and error methods.